Turbulent jet simulation using high-order DG methods for aeroacoustic analysis

This work deals with the application of a high-order discontinuous Galerkin (DG) method to predict the noise generated by a subsonic free jet at high Reynolds number ReD=106, based on the nozzle diameter. The large-eddy simulation (LES) technique is used to compute the turbulent flow dynamics and acoustics in the near field. The estimation of the far-field noise is made by means of the Ffowcs Williams and Hawkings surface integral formulation. A fourth-order DG simulation of this jet configuration is presented in this paper. The DG simulation is based on the Smagorinsky model and the computational grid employed is fully tetrahedral. This DG simulation is compared to an LES computation performed in previous work by means of a second-order finite-volume (FV) solver using a similar type of grid and SGS model. The results from the DG and FV computations are also compared to the available experimental data. It appears from this study that the DG computation is able to resolve higher-frequency components close to the nozzle exit, which is related to the better match found with the experimental data in the far field.